Abstract
Energy storage is a key enabling technology to facilitate an efficient system integration of intermittent renewable generation and support energy system decarbonisation. However, there are still many open questions regarding the design, capacity, and value of long-duration electricity storage (LDES), the synergy or competition with other flexibility technologies such as demand response, short-duration storage, and other forms of energy storage such as hydrogen storage. This paper presents a novel integrated formulation of electricity and hydrogen systems to identify the roles and quantify the value of long-duration energy storage holistically. A spectrum of case studies has been performed using the proposed approach on a future 2050 net-zero emission system background of Great Britain (GB) with a high share of renewable generation and analysed to identify the value drivers, including the impact of prolonged low wind periods during winter, the impact of different designs of LDES, and its competitiveness and synergy with other technologies. The results demonstrate that high storage capacity can affect how the energy system will evolve and help reduce system costs.